“My favourite is the Grim Gargoyles – that one has completely sold out already.

“It’s so moody, and the way Alex Ross has captured Batman’s determination on his face with the rain dripping off his face is very atmospheric.”

However the prints also come with a super-sized price tag – with some starting at £695 and ranging up to £6,000 for a framed collection.

Mr Pritchard added: “We’ve already sold 30 to 40 Stan Lee items and just two weeks into the Alex Ross exhibit we are already into double figures.

“It represents a great entry-level investment in fine art because there is such a worldwide collective of fans.

“Alex Ross as a comic artist is so well thought of and his exhibitions in the USA sold out every time.”

American-born Alex Ross is widely considered to be one of the most well-respected and prolific comic book artists within the field.

The 44-year-old artist has produced over 1,000 pages and covers for both DC Comics and Marvel throughout his impressive career.

For more information about the exhibition and the Castle Gallery in Leeds city centre, you can visit the website at www. castlegalleries.com/galleries/castle-galleries-leeds.

The legend of Stan Lee

Stan Lee is an iconic American comic book writer, editor and former president and chairman of Marvel Comics. Lee co-created Spider-Man, the Hulk, the X-Men, the Fantastic Four, Iron Man, Thor, the Silver Surfer, The Avengers and several other fictional characters.

Lee, who is now 91, is credited with introducing complex characters with flaws, making them more human and easier to identify with.